1. Field of the Invention
This invention relates to the art of steering trailer wheels under the control of the fifth wheel of a tractor in a conventional tractor semitrailer assembly and particularly deals with trailer mounted steering mechanisms coupled to and uncoupled from the standard fifth wheel of a tractor by a trailer mounted control.
2. Description of the Prior Art
Heretofore known systems for steering tractor wheels of tractor semitrailer vehicles have required special tractor mounted controls and mechanisms that were not easily uncoupled from the trailer so that it was not practical to provide trailer wheel power steering in tractor-trailer vehicles which were frequently uncoupled.
It would therefore be an improvement in this art to provide trailer mounted rear wheel power steering controlled by the standard tractor mounted fifth wheel coupled to the standard semitrailer kingpin.
It would be a further improvement in this art to provide a power steering system for the rear wheels of semi trailers which has a trailer mounted slide advancing and retracting a tongue into and out of coupling engagement with the fifth wheel of the tractor to control the system.
It would be a still further improvement in this art to provide a flexible control cable connection between a fifth wheel actuated trailer link and a control valve of a hydraulic trailer wheel power steering mechanism and it would be an additional improvement to provide a lost motion connection between the cable and valve to program the rear wheel steering for minimizing initial sudden swing-out of the extended end portion of the trailer.
Another feature of the invention is the provision of operation lights and alarms on the trailer to show when the power steering system is in an operating mode and to warn against abnormal steering conditions as in making extremely sharp turns for docking and when driving on rough roads.